Electrical Skin Resistance Technic Used to Map Areas of Skin Affected by Sympathectomy and by Other Surgical or Functional Factors

During the past two years we have shown by means of the electrical skin resistance method, or measurement of the resistance offered to passage of minute direct current through the skin, (1) that areas of skin affected by upper thoracic or lumbar sympathectomy can be sharply defined on any part of the body, such areas having an abnormally high resistance; (2) that the patterns of these areas closely correspond to the sensory dermatomes and to areas which do not sweat, as was demonstrated by the Minor starch-iodine-sweating test (Richter and Woodruff¹); (3) that areas affected by injection of procaine or alcohol into the sympathetic chain can be quickly and sharply defined, often within a few minutes after injection (Shumacker²), and (4) that the skin of normal persons manifests rather constant and hitherto entirely unsuspected areas of low electrical skin resistance on the face, hands, feet, axillas and antecubital